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Musculoskeletal system: 1.7a The axial skeleton – neck 247

VetBooks.ir Aetiology/pathophysiology 1.468
Aseptic degeneration, traumatically-induced injury
and infectious discospondylitis have been recognised.

Clinical presentation
Clinical features are related in part to the region of
the neck involved. Neck stiffness and neck pain, with
or without difficulties in lowering the head and neck
to graze, are the most common clinical features.
There may or may not be associated neurological
signs.
Fig. 1.468 Laterolateral radiograph and myelogram
Diagnosis of a young foal with a septic bone abscess within the
Diagnosis is based on good-quality true laterolateral cranial aspect of the third cervical vertebra. Note the
radiographs. There is marked loss of the intercentral collapse of the third vertebra and the caudal part of the
joint space (Fig. 1.467) with, or without, changes in second vertebra, plus narrowing of the ventral column
the caudal end plate of the more cranial vertebra and of contrast medium immediately dorsal to the affected
the head of the more caudal vertebra. intercentral joint. (Photo courtesy Jane Boswell)

Management
Surgical fusion could be considered. bone (Fig. 1.468). There may be an increase in
serum amyloid A and fibrinogen concentrations.
VERTEBRAL OSTEOMYELITIS
Management
Definition/overview Cervical osteomyelitis is often challenging to man-
Infection of one or more cervical vertebrae is very age successfully, and the prognosis is guarded to
rare. poor. Long-term appropriate antimicrobial therapy
is essential in any treatment plan.
Aetiology/pathophysiology
Infection in a foal may be secondary to Rhodococcus SUBLUXATION
equi infection. Avian tuberculosis has been recog-
nised in adult horses. Extension into the cervical Definition/overview
vertebrae has also occurred from neck abscesses post Misalignment of two adjacent vertebrae in the sagit-
intramuscular injections. tal plane, or subluxation, results in a change in orien-
tation of the vertebral canal from cranial to caudal.
Clinical presentation If the sagittal diameter of the vertebral canal is
There is neck stiffness due to bone pain. large, there may be no associated clinical signs, and
this can be an incidental radiological abnormality
Differential diagnosis (Fig. 1.469). However, with a smaller vertebral canal
Multiple myeloma and other neoplastic conditions. there is the potential for spinal cord compression
and ataxia and weakness. Lesions have been identi-
Diagnosis fied most commonly between the third and fourth
Diagnosis is based on radiological, haematological cervical vertebrae. Less commonly, lesions occur in
and bone biopsy examinations. There are usually the caudal neck region involving the fifth and sixth
lucent zones within one or more vertebrae, which or sixth and seventh cervical vertebrae, or the sev-
may be surrounded by a rim of more radiopaque enth cervical and first thoracic vertebrae.